Boiler



v(No Model.)

C. SPRAGUE.

BOILBR.

Patented Nov. 11, 1890.

UNO. 440,284.-

Nire

OARLETON SPRAGUE, OF BUFFALO, NEV YORK.

BOILER.

SPECIFICATION forming part of Letters Patent No. 440,284, dated November 11, 1890.

Application filed May 2, 1890. Serial No. 350,280. (No model.)

To all whom 15 may concern:

Be it known that I, CARLETON SPRAGUE, of Buffalo, in the county of Erie, in the State of New York, have invented new and useful Improvements in Boilers, of which the following,

previously devised; and to this end it consists,

essentially, in a boiler-shell having an upward extension, an annular bearing or ring provided upon the outside of said extension, a smoke-box removably secured to said bearing, whereby the said combustion-box may be readily removed when defective or Worn out and replaced by a new one at a minimum cost and without necessitating the replacement of the entire boiler-shell extension.

The invention also consists in providing` said ring or removable combustion-box with a bearing in front of the securing-point of the rear flue-sheet and in forming the said bearing of greater thickness than the securing-rivets for said nue-sheet, whereby the mounting and removing of said combustionbox are enabled without necessitating the slightest injury to said securing-rivets- The invention still furthermore consists in the detail construction and arrangement of the parts, all as hereinafter more particularly described, and pointed out in the claims.

In describing this invention reference is had to the accompanying drawings, forming a part of this specification, in which like letters indicate corresponding parts in all the views.

Figure l represents a longitudinal vertical section illustrating the relative construction and arrangement of the parts of my improved construction of boiler. Fig. 2 is an end elevation of the boiler-extension with the cap or cover thereof removed for the purpose of illustration, and Fig. 3 is an enlarged sectional detail view illustrating the means for securing the flue-sheet and removable combustion-box to the boiler-shell extension.

AA represents the boiler shell or casing formed of suitable size and material and provided with the forward extension A', which is preferably of circular form. Secured to the boiler-shell and its extension are the front and rear flue-sheets B and C.

The re-box D is of any suitable construction, size, or shape, and is provided with adesirable form of grate E. `Opening from the lire-box D is the iire flue or passage F, secured at its rear extremity to the rear flue-sheet C and preferably to a forwardly-turned liange c near the base of said flue-sheet.

Provided upon the extension A', and preferablyin front of the securing-rivets c of the rear flue-sheet, is a bearing G, which preferably consists of a wrought-iron ring operatively secured by rivets orother suitable means g. As best seen in Fig. 3, the said ring G is of greater thickness than the head c2 of the securing means c', and supported upon said ring is the combustion-box H, of suitable size. This combustion-box is removably held in operative position by means of screws or other securing means g', which, as best shown in Fig. 2, are arranged at intervals around the forward extremity of said combustion-box and serve to effect a tight joint with the boilershell extension.

In boilers of this class, in order to produce perfect operation and the desired combustion of the gases, a rear combustion-box is a necessity. As heretofore constructed, this combustion-box has generally been formed separable from the boiler-shell extension and has had one extremity secured to the rear flue-sheet for supporting said line-sheet and the other extremity secured to the extremity of the boiler-shell extension. Experience has demonstrated that the products of combustion rush through the fire-flue F into the combustion-box H, which they heat to a great temperature, and in the aforesaid construction of boiler I have found that an inadequate amount of water surrounds the combustionbox, especially when the Water is low, and that thereby the great heat developed cracks or quickly burns out the combustion-box, and

its replacement can only be effected at a great cost for time and labor. Moreover, in this IOO combustion-box of greater diameter than the boiler-shell extension, thereby increasing the area of the combustion-box, and I removably secure said shell to the boiler-shell extension, and thus enable the ready replacement of a Worn combustion box at a minimum expense for material.

It Will be particularly noted that my improved combustion-box has no Water-joints Whatever, and thereby all leakage is absolutely prevented. Moreover, the said oombustion-box may be composed of cast-iron instead of Wrought-iron, which must necessarily be the material for combustion-boxes supported Within the boiler-shell extension, and thereby the cost of my improved boiler is greatly decreased;

In order to prevent the direct contact of the products of combustion with the inner surface of the removable combustion-box H, I provide any suitable construction of baffleplate I. As illustrated, this bathe-plate is composed of the angularly-bent top lportionvl and the rounding extremities i', and is supported by eyebolts 2, whereby when burned out, its replacement is enabled Without 11ecessitating the use of skilled labor.

My invent-ion is ot' particular advantage When used in traction-engines, since it frequently occurs that the combustion-box is burned out or injured when far removed from skilled laborand boiler-shops, and in this case by providing himself with additional combustion-boxes the user or owner of the boiler can quickly and with unskilled labor remove the old combustion-box and replace it With a new one, and Without necessitating the stoppage of operations but for a short time.

The operation of my invention will be readily perceived from the foregoing, and it will be understood that I do not limit my invention to the precise detail construction of its parts, since the same may be Vsomewhat varied Without departing from the spirit thereof.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a boiler, the combination of a boilershell having an extension, an annular bearing provided on the outside of said extension, a combustion-box encircling said bearing, and screws for removably securing said box to said bearing, substantially as and for the purpose described. V c

2. In a boiler, the combination of a boilershell having an extension, a rear flue-sheet, rivets for securing said flue-sheet to said eX- tension, an annular ring secured to the out` side of said extension in front of said securing-rivets, said ring being formed of greater thickness than the adjacent heads of said rivets, and acombustion-box removably secured to said ring, substantially as and for the purpose speciied.

3. In a boiler, the combination of a boilershell having an extension, an annular bearing provided on the outside of said extension, a combustion-box'encirclin g said bearing, movable clamps for removably securing said box to said bearing, a fire-line F, discharging Within said combustion-box, and return-dues leading from said combustion-box, substantially as and for the purpose specified.

In testimony whereof I have hereunto signed my name, in the presence of two attesting Witnesses, at Buffalo,in the countyof Erie, in the State of New York, this 29th day April, 1890.

CARLETON SPRAGUE. 

